Neuroendocrine Tumours

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Neuroendocrine Tumours
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Neuroendocrine Tumours

• Heterogenous group of neoplasms
• Share certain characteristic features
• Originate from neuroendocrine cells
• Have secretory characteristics
• Frequently present with hypersectretory syndromes

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Neuroendocrine Tumours

• Pancreatic islet cells
• Gastroenteric tissue
• Respiratory epithelium
• Gastroenteropancreatic NETs
• Includes carcinoid (serotonin secreting tumour)

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Presentation

• Asymptomatic
• Present with obstructive symptoms
• Symptoms
• Usually due to liver metastases
• Release of hormones into circulation e.g.
  Serotonin, tachykinin

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Symptoms

• Intermittent abdo pain 70
• Diarrhoea 50
• Flushing 30
• Lacrimation
• Rhinorrhoea
• Episodic palpitations
• Wheezing
• Pellagra

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Carcinoid crisis

• Precipitated by
• Anaesthetic induction
• Intraoperative tumour handling
• Therapeutic procedures, eg embolisation
• Profound flushing
• Bronchospasm
• Tachycardia
• Widely fluctuating BP

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Aetiology and Genetics

• Poorly understood
• Most are sporadic
• Small increased familial risk for small
  intestinal / colonic tumours
• Aim to exclude complex cancer syndromes (e.g. MEN
  1, MEN 2, NF1)

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Diagnosis

• Clinical symptoms
• Hormone concentrations
• Radiology
• Histology gold standard

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Hormone concentrations

• Plasma chromagranin A (CgA)
• May correlate with response and relapse
• Fast rising levels poor prognosis
• Urine 5-HIAA (24 hrs)
• Certain foods affect urinary excretion and may
  cause false positives
• Pancreatic polypeptide
• High concentration in 80 pancreatic and 50
  carcinoid
• Should also measure other hormones for MEN
  syndromes.

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Imaging Sensitivites () of various imaging
modalities for locating specific neuroendocrine
tumours
Primary carcinoid tumour Carcinoid liver mets
Ultrasound 46 83
CT 64 88
MRI 56 85
SSRS 80 90
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Imaging

• 40-70 of patients have nodal or liver
  metastases at time of presentation
• If lt2 cm diameter low incidence of metastases

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Small intestinal carcinoid Treatment

• Aim should be curative
• Palliation in majority of cases
• Majority are malignant
• Resection of primary and mesenteric lymph nodes
  despite liver mets
• For cure / delay progression (could endanger
  small bowel)
• Can alleviate symptoms
• ? Prolong survival

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Symptomatic Treatment

• Used in patient with secretory symptoms
• Somatostatin analogues (e.g. Octreotide)
• Inhibits release of many hormones
• Can impair some exocrine functions
• Hormone response in 30-70 patients
• Symptom control in majority
• Rarely tumour shrinkage

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Additional medication

• Ondansatron
• nausea
• Cyproheptadine
• Cholestyramine
• CREON
• Control of diarrhoea, esp after intestinal
  resection

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Interferon alpha

• Sole use or with somatostatin analogues
• ? Efficacy (conflicting evidence)
• Some evidence better in tumour with low mitotic
  rates
• Biochemical response 40-60
• Symptomatic improvement 40-70
• Significant tumour shrinkage 10-15

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Other options

• Chemotherapy
• Role uncertain but being actively researched
• Response short lived (8-10 months)
• Hepatic artery embolisation
• Indicated for non resectable multiple hormone
  secreting tumours
• Causes ischaemia of tumour cells
• Symptomatic response 40-80
• 5 year survival 50-60

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• Radionucleotide therapy
• Palliative option
• Exploits increased uptake of radiolabelled
  isotopes I-MIBG or octreotide
• Symptom control 80
• Radiotherapy
• Carcinoid radioresistant
• Relief of pain from bone mets

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Prognosis

• No TNM classification
• Slow growing, but survival depends on
• Histological type
• Degree of differentiation
• Mitotic rate
• Tumour size
• Depth and location
• Lymph node/ liver metastases

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Prognosis 5 year survival